From Sahih Bukhari (Hadith 931):
Narrated Jabir:A man entered the Mosque while the Prophet (ﷺ) was delivering the Khutba. The Prophet (ﷺ) said to him, "Have you prayed?" The man replied in the negative. The Prophet (ﷺ) said, "Pray two rak`at
Reference: Bukhari 931